Ji D, etal., Carcinogenesis. 2013 Jun;34(6):1265-72. doi: 10.1093/carcin/bgt056. Epub 2013 Feb 7.
This study was designed to develop novel and better reliable serum prognostic biomarkers for colorectal cancer (CRC). A 50 sample set including CRC, adenoma and healthy control sera was used to identify the serum proteins involved in CRC carcinogenesis using serum proteomic approach. Alpha-2-glycopr
otein 1, zinc-binding (AZGP1), pigment epithelium derived factor (PEDF) and peroxiredoxin 2 (PRDX2) were selected as good candidates. Two independent cohorts of 868 individuals were enrolled. The expression of selected proteins in serum from cohort 1 (n = 534) was quantified with enzyme-linked immunosorbent assays. CRC sera of this cohort (n = 405) were assigned to training and test sets, which were used to identify and verify the prognostic markers. The prognostic values of identified proteins were further validated in cohort 2 (n = 334) using quantitative reverse transcription PCR and immunohistochemical staining. Our data showed that the elevated AZGP1 and decreased PEDF and PRDX2 expressions in CRC serum and tissues were correlated with liver metastases. In the training set, higher AZGP1 and lower PEDF levels in sera were significantly associated with a poorer overall survival (OS), higher AZGP1 was also associated with a poorer disease-free survival (DFS). This association was verified in the testing set and further validated in patients in cohort 2. Patients with lower PEDF or PRDX2 levels in their CRC tissues had a significantly poorer DFS or OS than patients with high levels of these proteins in cohort 2. Univariate and multivariate analyses indicated that the prognostic performance of serum AZGP1 and PEDF was independent of other clinicopathological factors. We propose that they may serve as prognostic markers and potential therapeutic targets in CRC.
Oxidative stress is involved in the pathogenesis of hypertension and hypertensive organ damage. Our previous study suggested that stroke-prone spontaneously hypertensive rats (SHRSP) exhibited greater oxidative stress than SHR and that the stroke incidence was significantly greater in SHRSP than SHR
. Therefore, we hypothesized that oxidative stress was responsible for the stroke susceptibility in SHRSP. The present study constructed Prdx2 (a gene coding an antioxidative enzyme)-knockout (KO) SHR to examine whether Prdx2 knockout would make SHR more vulnerable to hypertensive organ damage, including stroke. Prdx2-KO SHR were created using CRISPR/CAS9 for genome editing. Eight-week-old male SHR and Prdx2-KO SHR were fed 1% NaCl for 2 months to induce blood pressure (BP) changes and stroke occurrence. The baseline BP was significantly greater in KO SHR, and this difference disappeared after salt loading. The life span of KO SHR was significantly reduced compared to that of SHR despite no differences in BP under salt-loading. However, no stroke was observed in KO SHR. The severity of hypertensive renal and cardiac injuries did not differ significantly between the two strains, but oxidative stress, evaluated using urinary isoprostane excretion and DHE staining, was greater in KO SHR. These results indicated that the Prdx2-depletion caused a shorter life span and modest BP increase in SHR via increased oxidative stress. The pathophysiological roles of oxidative stress in this model should be clarified in future studies.
Psoriasis is a chronic inflammatory skin disease, characterized by a combination of abnormal proliferation of keratinocytes, immunology and vascular proliferation. Proteomic analyses have revealed some clues regarding the pathogenesis of psoriasis. In the present study, we conducted an investigation
of different proteomes of psoriatic lesional skin, and compared them with those of normal and non-lesional psoriatic skin. We performed 2-D gel electrophoresis, liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis and database searches. Expression of proteins were evaluated by immunoblot and immunohistochemistry analyses. Our data showed differential expression of 74 and 145 protein spots in non-lesional and lesional psoriatic skin, respectively. Eleven of 36 proteins, which were identified by LC-MS/MS, were categorized as apoptosis-regulating proteins. Other protein spots were categorized as proteins with involvement in the negative regulation of apoptosis, defense response-related proteins and inflammatory response. Of particular interest, increased expression of glutathione S transferase 1 (GSTP1) and peroxiredoxin 2 (PRDX2), which are involved in the Redox balance system, and SFN, which is involved in the cellular proliferation system, was observed in psoriatic lesional skin. Localization of GSTP1 and SFN was observed above the middle layer of the epidermis in psoriatic skin lesions. Expression of PRDX2 was clearly observed below the middle layer of the epidermis in chronic type psoriatic skin lesions. Taken together, 36 identified proteins were associated with biological regulation, including regulation of cell death, defense response, inflammatory response and reactive oxygen species (ROS) regulation. PRDX2 and GSTP1 may play roles in compensating mechanisms for reduction of ROS stress, and SFN may play roles in prevention of cancer development in proliferating cells through G2/M cell cycle arrest upon accidental DNA damage within psoriatic skin lesions.
